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Related papers: Generic immersions and totally real embeddings

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We show that a pseudo-holomorphic embedding of an almost-complex $2n$-manifold into almost-complex $(2n + 2)$-Euclidean space exists if and only if there is a CR regular embedding of the $2n$-manifold into complex $(n + 1)$-space. We remark…

Differential Geometry · Mathematics 2018-04-24 Rafael Torres

Ahern and Rudin have given an explicit construction of a totally real embedding of $S^3$ in $\mathbb{C}^3$. As a generalization of their example, we give an explicit example of a CR regular embedding of $S^{4n-1}$ in $\mathbb{C}^{2n+1}$.…

Geometric Topology · Mathematics 2019-12-06 Naohiko Kasuya

We shall prove that there are totally real and real analytic embeddings of $S^k$ in $\cc^n$ which are not biholomorphically equivalent if $k\geq 5$ and $n=k+2[\frac{k-1}{4}]$. We also show that a smooth manifold $M$ admits a totally real…

Complex Variables · Mathematics 2008-02-03 Xianghong Gong

It is shown that any smooth closed orientable manifold of dimension $2k + 1$, $k \geq 2$, admits a smooth polynomially convex embedding into $\mathbb C^{3k}$. This improves by $1$ the previously known lower bound of $3k+1$ on the possible…

Complex Variables · Mathematics 2020-09-29 Purvi Gupta , Rasul Shafikov

It is proved that any smooth manifold $\mathcal M$ of dimension $m$ admits a smooth polynomially convex embedding into $\mathbb C^n$ when $n\geq \lfloor 5m/4\rfloor$. Further, such embeddings are dense in the space of smooth maps from…

Complex Variables · Mathematics 2025-04-03 Purvi Gupta , Rasul Shafikov

We show that a compact orientable 4-manifold M has a CR regular immersion into C3 if and only if both its first Pontryagin class and its Euler characteristic vanish, and has a CR regular embedding into C3 if and only if in addition the…

Complex Variables · Mathematics 2015-05-19 Marko Slapar

In this article, we show that there exists no CR-regular embedding of the 5-sphere $S^5$ into $\mathbb{C}^4$, and also obtain analogous results for embeddings of higher dimensional spheres into complex space.

Complex Variables · Mathematics 2018-11-08 Ali M. Elgindi

In this article we show that every closed orientable smooth $4$--manifold admits a smooth embedding in the complex projective $3$--space.

Geometric Topology · Mathematics 2020-06-29 Abhijeet Ghanwat , Dishant M. Pancholi

We prove that the existence of totally real immersions of manifolds is a closed property under cut-and-paste constructions along submanifolds including connected sums. We study the existence of totally real embeddings for simply connected…

Complex Variables · Mathematics 2018-05-29 Marko Slapar , Rafael Torres

For each composite number $n\ne 2^k$, there does not exist a single connected closed $(n+1)$-manifold such that any smooth, simply-connected, closed $n$-manifold can be topologically flat embedded into it. There is a single connected closed…

Geometric Topology · Mathematics 2007-05-23 Fan Ding , Shicheng Wang , Jiangang Yao

A stable smooth map $f:N\to M$ is called "$k$-realizable" if its composition with the inclusion $M\subset M\times\Bbb R^k$ is $C^0$-approximable by smooth embeddings; and a "$k$-prem" if the same composition is $C^\infty$-approximable by…

Geometric Topology · Mathematics 2021-05-13 Peter M. Akhmetiev , Sergey A. Melikhov

We improve results of Baouendi, Rothschild and Treves and of Hill and Nacinovich by finding a much weaker sufficient condition for a CR manifold of type $(n,k)$ to admit a local CR embedding into a CR manifold of type $(n+\ell,k-\ell)$.…

Complex Variables · Mathematics 2022-04-05 M. G. Cowling , M. Ganji , A. Ottazzi , G. Schmalz

A 2-cell embedding of a graph $G$ into a closed (orientable or nonorientable) surface is called regular if its automorphism group acts regularly on the flags - mutually incident vertex-edge-face triples. In this paper, we classify the…

Combinatorics · Mathematics 2010-01-19 Jin Ho Kwak , Young Soo Kwon

Using a bigraded differential complex depending on the CR and pseudohermitian structure, we give a characterization of three-dimensional strongly pseudoconvex pseudo-hermitian CR-manifolds isometrically immersed in Euclidean space…

Differential Geometry · Mathematics 2012-02-21 Andrea Altomani , Marie-Amélie Lawn

Let $X$ be a CR manifold with transversal, proper CR $G$-action. We show that $X/G$ is a complex space such that the quotient map is a CR map. Moreover the quotient is universal, i.e. every invariant CR map into a complex manifold…

Complex Variables · Mathematics 2020-02-04 Kevin Fritsch , Peter Heinzner

We show that any compact smooth real $n$-dimensional manifold $M$ with $n\leq 11$ can be smoothly embedded into $\mathbb{C}^{n+1}$ as a polynomially convex set. In general, there is no such embedding into $\mathbb{C}^n$. This solves a…

Complex Variables · Mathematics 2026-04-21 Leandro Arosio , Håkan Samuelsson Kalm , Erlend F. Wold

We apply the general theory of codimension one integrability conditions for $G$-structures developed in arXiv:1306.6817v3 [math.DG] to the case of quaternionic CR geometry. We obtain necessary and sufficient conditions for an almost CR…

Differential Geometry · Mathematics 2017-04-10 Andrea Santi

We investigate the problem of approximating a regular Sasakian structure by CR immersions in a standard sphere. Namely, we show that this is always possible for compact Sasakian manifolds. Moreover, we prove an approximation result for…

Differential Geometry · Mathematics 2024-02-21 Giovanni Placini

We prove that any compact almost complex manifold $(M, J)$ of real dimension $2m$ admits a pseudo-holomorphic embedding in a Euclidean space of dimension $4m + 2$, endowed with a suitable non-standard almost complex structure. Moreover, we…

Differential Geometry · Mathematics 2016-02-26 Antonio J. Di Scala , Naohiko Kasuya , Daniele Zuddas

E. Cartan's method of moving frames is applied to 3-dimensional manifolds $M$ which are CR-embedded in 5-dimensional real hyperquadrics $Q$ in order to classify $M$ up to CR symmetries of $Q$ given by the action of one of the Lie groups…

Differential Geometry · Mathematics 2021-02-23 Curtis Porter
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